PALMINE may be prepared from the castor oil, and possibly from other oils also, by treating them with nitric or nitrous acids. A process is given in Brande's Manual of Chemistry, xi. p. 1257, and is supposed to be the substance which was, about A.D. 1857, patented for the use of rail way carriages in British India ; and whether as regards its origin, the facility of making it, the abundance of the castor-oil plant in India, its con sistence and cheapness, it well deserves attention. When nitrous or nitric acid is made, to act upon castor-oil, it is converted into a solid wax-like substance ; and a similar, though much more rapid, result takes place when this oil or olive oil are similarly treated with nitrate of mercury. Castor oil is the only one of the drying oils which is susceptible of this species of solidification. On adding nitrous acid to castor-oil, a yellow liquid is at first formed, and the time required for its solidi fication varies with the quantity of acid employed ; when about a twentieth part of acid is used, it solidifies in seven or eight hours, and this or somewhat less is the best proportion. If too
much acid be used, a third part, for instance, or a half, the temperature rises to 130°, or 140° ; effervescence ensues, and the oil becomes opaque, and instead of indurating remains viscid. Palmine thus obtained is yellow, but when purified by solution in boiling alcohol, it is white, of a waxy fracture, and requires a temperature of about 150° for its fusion. When this is kept for some months, it occasionally acquires a resinous appearance, and presents an almost vitreous fracture. A large and profitable trade might be had in palmine made from the cheap oils of Southern Asia, the difficulty of transporting which while fluid is well known.